19 research outputs found

    Cycling traffic at turbo roundabouts: some considerations related to cyclist mobility and safety

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    Abstract The growing need for sustainable mobility has led the transport policy-makers as well as population to use more of soft mobility solutions such as pedestrian and cycling traffic. Several European countries are implementing policies for total mobility with less motorization in order to reduce the negative environmental effects generated by industries and transport. In the same time new unconventional types of intersections are developed in order to ensure safer conditions not only for motorized traffic but also for pedestrians and cyclist. One of those is turbo roundabout, at-grade two-lane roundabout, introduced also in urban areas where heterogeneous traffic users are expected and on which traffic safety should be considered carefully. This article aims to analyze the safety of cyclists in different traffic conditions at turbo roundabout with and without separated traffic lanes for cyclists. Through the evaluation of level of service and surrogate safety parameters, the advantages and critical aspects linked to turbo roundabout are highlighted. The research will be conducted on theoretical turbo roundabout with substantial variation in traffic flow. Comparison of the results will allow a better understanding of functionality (level of service, traffic safety) of turbo roundabout in the presence of pedestrians and cyclists of different age. The aim of this article is to present possible solutions to enable safer introduction of cycling traffic at turbo-roundabouts and help defining conditions (number of vehicles, number of cyclist, and number of pedestrians) in which safety of cyclist is questionable and there is need for different solution

    Comparison of red-light running (RLR) and yellow-light running (YLR) traffic violations in the cities of Enna and Thessaloniki

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    Abstract This paper investigates the characteristics of Red-Light Running (RLR) and Yellow-Light Running (YLR) traffic violations at three signalized intersections which are located in the city of Enna, Italy, and four signalized intersections which are located in the city of Thessaloniki, Greece. The trigger for this particular research is that there are cases in the literature in which the driving styles, as far as compliance with the Highway Code regulations is concerned, change from city to city and from country to country. Two sets of counts were used in the framework of this paper in order to investigate this phenomenon. The first one concerns the year 2018 in Enna and the second one the year 2015 in Thessaloniki. Descriptive and inferential statistics were used in order to analyze the collected data and more specifically to investigate the correlation between the violations at signalized intersections in both cities. One of the most important findings of the specific research is that private cars are the responsible for the vast majority of the violations at the signalized intersections. In addition, it was found that traffic lane plays a significant role in the under study traffic violations

    Redox and autonomic responses to acute exercise-post recovery following Opuntia ficus-indica juice intake in physically active women

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    Background: The aim of this study was to investigate if the supplementation with Opuntia ficus-indica (OFI) juice may affect plasma redox balance and heart rate variability (HRV) parameters following a maximal effort test, in young physically active women. Methods: A randomized, double blind, placebo controlled and crossover study comprising eight women (23.25 ± 2.95 years, 54.13 ± 9.05 kg, 157.75 ± 0.66 cm and BMI of 21.69 ± 0.66 kg/m2) was carried out. A juice containing OFI diluted in water and a Placebo solution were supplied (170 ml; OFI = 50 ml of OFI juice + 120 ml of water; Placebo = 170 ml beverage without Vitamin C and indicaxanthin). Participants consumed the OFI juice or Placebo beverage every day for 3 days, before performing a maximal cycle ergometer test, and for 2 consecutive days after the test. Plasma hydroperoxides and total antioxidant capacity (PAT), Skin Carotenoid Score (SCS) and HRV variables (LF, HF, LF/HF and rMSSD) were recorded at different time points. Results: The OFI group showed significantly lower levels of hydroperoxides compared to the Placebo group in pretest, post-test and 48-h post-test. PAT values of the OFI group significantly increased compared to those of the Placebo group in pre-test and 48-h post-test. SCS did not differ between groups. LF was significantly lower in the OFI group 24-h after the end of the test, whereas rMSSD was significantly higher in the OFI group 48-h post-test. Conclusion: OFI supplementation decreased the oxidative stress induced by intense exercise and improved autonomic balance in physically active women

    Theoretical Determination of the pK a Values of Betalamic Acid Related to the Free Radical Scavenger Capacity: Comparison Between Empirical and Quantum Chemical Methods

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    Health benefits of dietary phytochemicals have been suggested in recent years. Among 1000s of different compounds, Betalains, which occur in vegetables of the Cariophyllalae order (cactus pear fruits and red beet), have been considered because of reducing power and potential to affect redox-modulated cellular processes. The antioxidant power of Betalains is strictly due to the dissociation rate of the acid moieties present in all the molecules of this family of phytochemicals. Experimentally, only the pK a values of betanin were determined. Recently, it was evidenced it was evidenced as the acid dissociation, at different environmental pHs, affects on its electron-donating capacity, and further on its free radical scavenging power. The identical correlation was studied on another Betalains family compound, Betalamic Acid. Experimental evidences showed that the free radical scavenging capacity of this compound drastically decreases at pH > 5, but pK a values were experimentally not measured. With the aim to justify the Betalamic Acid behavior as free radical scavenger, in this paper we tried to predict in silico the pK a values by means different approaches. Starting from the known experimental pK as of acid compounds, both phytochemicals and small organic, two empirical approaches and quantum-mechanical calculation were compared to give reliable prediction of the pK as of Betalamic Acid. Results by means these computational approaches are consistent with the experimental evidences. As shown herein, in silico, the totally dissociated species, at the experimental pH > 5 in solution, is predominant, exploiting the higher electron-donating capability (HOMO energy). Therefore, the computational estimated pK a values of Betalamic Acid resulted very reliable

    The Effects of Red-Grape Seed and Pomace-Flour Dietary Supplementation on Broiler Chickens

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    Wine by-products, generated in large quantities and wasted with serious environmental and economic consequences, are an exceptional alternative to conventional and non-sustainable food sources. The aim of the study was to understand if these by-products could be reused in feed for broiler chickens, improving certain blood parameters important in immune responses, by testing different concentrations and administration times. The effects of the grape-seed and pomace flour of red-wine waste were evaluated. Three different diets were tested containing pomace (0%, 3%, and 6%), grape seeds (0%, 3%, and 6%), and a mix of pomace and grape seeds (0 and 3%) for 7, 21, and 42 days. Esterase, alkaline phosphatase, and peroxidase activity, along with glucose, reactive oxygen species, and glutathione levels, were evaluated in blood samples. The results showed significant changes in the parameters analyzed, especially after 21 and 42 days of administration. All diets administered showed significant effects based on exposure time and by-product concentration used. The greatest effects seem to have come from grape-seed flour. All the by-products of wine production analyzed in this study showed important antioxidant activities and can be included in the food context of farm animals in different growth phases at different concentrations

    The Surrogate Safety Appraisal of the Unconventional Elliptical and Turbo Roundabouts

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    Double-lane roundabouts have been created in many European countries over the past few centuries and are now characterized by an unsafe geometric development and by a low sustainability capacity or level. In this regard, new double-lane geometries have been implemented to overcome to these critical points. This article shows a comparison of two nonconventional double-lane roundabout schemes defined as elliptical and turbo. Considering this research on the unsafe and congested conditions for each road schemes at grade, the microsimulation approach allows comparing schemes of intersections not yet realized in order to be able to evaluate the critical issues. A symmetric traffic distribution and an identical vehicle mix for both design solutions are considered. The research was conducted considering two different double-lane roundabout-turbo roundabout and the elliptical roundabout. By comparing their geometry and technical elements, this article assumes that turbo roundabout due to its physical separating traffic lanes in the central circulatory carriageway will enable potentially better traffic safety conditions. This article has the following main goal: a comparison of traffic safety using VISSIM microsimulator and SSAM tools. The results can provide to show safety level on investigated scenario considering level of service (LOS) and also the possibility of obtaining time to collision (TTC) and postencroachment time (PET) through the use of surrogate parameters obtained by SSAM tool. In fact, the surrogate safety parameters allows evaluating the possible collision scenarios between them, according to the trajectories of the single vehicles. This assessment is useful in order to be able to evaluate by the local authorities which of the examined schemes can provide greater negativity in the construction and operation phase. Therefore this comparative analysis allows reducing, in the preliminary phase, possible security impacts and also economic ones for the community

    The Importance of Assessing the Level of Service in Confined Infrastructures: Some Considerations of the Old Ottoman Pedestrian Bridge of Mostar

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    Walking is classified as the oldest transport mode with the least impact on the environment. It is frequently one of the intermediate transport modes. Generally, while designing exclusive walking transit areas or structures with high human traffic volumes and considering different scenarios, it is advantageous to be able to foresee the congestion conditions and the relative problems. The study of pedestrian trajectories, which are strictly related to the characteristics of the walkers, is necessary and preliminary for the purposes of an in-depth analysis linked to the habits of populations and cultures. Often areas crowded by tourists run, of limited size such as bridges, must be considered in advance for emergencies. This article focuses on an old footbridge of Mostar located in a confined area with an increasing tourist flow. The peculiarity of the bridge lies in the double-flight geometry with elements that generate discontinuity in the trajectory as well as the steps. This analysis was carried out obtaining the traffic data from video cameras and analyzing different scenarios on holidays and weekdays. Also, the possible presence of obstacles on the bridge was taken into account, such as some areas not walkable for temporary work or the presence of obstacles. These scenarios have been calibrated and simulated through the definition of O/D matrices, arcs and nodes (or areas) through the pedestrian simulation tool Viswalk. This comparison is useful for understanding the variation of LOS (Level of Service) during the daily or emergency situations and the results can provide help to local authorities to plan and design an appropriate action plan. Therefore, this research work aims to compare scenarios under critical flow conditions in the order to define preventively possible actions that can guarantee an optimal LOS value during the bridge crossing and the surrounding areas

    Smart Pedestrian Crossing Management at Traffic Light Junctions through a Fuzzy-Based Approach

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    In the last few years, numerous research efforts have been conducted to merge the Internet of Things (IoT) with smart city environments. The goal to make a city “smart” is arising as a possible solution to lessen the issues caused by the urban population growth and fast urbanization. Attention also has focused on the pedestrian crossings because they are one of the most dangerous places in the transport field. Information and Communications Technologies (ICT) can undoubtedly be an excellent support in developing infrastructures that can best manage pedestrian crossing. For this reason, this paper introduces a fuzzy logic-based solution able to manage dynamically the traffic lights’ phases in signalized pedestrian crossings. The proposed approach provides the possibility to change the phases of the traffic light taking into account the time of the day and the number of pedestrians about to cross the road. The paper presents a thorough description of the fuzzy logic controller configuration, an in-depth analysis of the application scenario and simulative assessments obtained through Vissim simulations
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